Following their come-from-behind 2-1 win over Everton on Tuesday, the Gunners find themselves five points behind leaders United.

While City's hopes foundered with a 2-2 draw at Birmingham on Wednesday, Chelsea look resurgent after romping to a 4-2 success at Sunderland, fuelling speculation that they could yet catch United, who they are yet to face this season.

Koscielny remains unimpressed by their credentials, despite the signings of Fernando Torres and David Luiz, as he feels the Gunners are putting together the most meaningful pursuit.

"It looks like we are the last challengers to United," he said. "We have got more points than Manchester City, Chelsea and the others. We need to focus on our game, keep winning, keep picking up points and maybe United will lose games at some point.

"Anything can happen in this league. That's why we must keep working hard together. We will keep fighting. It's important we keep our defence strong. If we don't concede, we will always make chances to score ourselves.

"It's going to be a big battle between us and Manchester United and hopefully they will drop points, not us. It's not going to be easy. But we have faith in ourselves and in the squad. We do believe we can do it so bring it on."

After an unconvincing start to the season, Koscielny's form has improved in recent weeks - and goals against Ipswich and Everton have done much to endear him to the Arsenal fans. He admits that he found the physicality of the league challenging at first, but insists the difficult spell is now behind him.

"It wasn't easy for me but I feel stronger," he said. "I definitely feel like a better player than when I arrived here. In the last two months I have felt I've improved a lot."